Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Implications of various phosphoenolpyruvatecarbohydrate phosphotransferase system mutations on glycerol utilization and poly (3-hydroxybutyrate) accumulation in Ralstonia eutropha H16 | Kaddor and Steinbuchel AMB Express 2011 1 16 http content 1 1 16 o AMB Express a SpringerOpen Journal ORIGINAL Open Access Implications of various phosphoenolpyruvatecarbohydrate phosphotransferase system mutations on glycerol utilization and poly 3-hydroxybutyrate accumulation in Ralstonia eutropha H16 Chlud Kaddor and Alexander Steinbuchel Abstract The enhanced global biodiesel production is also yielding increased quantities of glycerol as main coproduct. An effective application of glycerol for example as low-cost substrate for microbial growth in industrial fermentation processes to specific products will reduce the production costs for biodiesel. Our study focuses on the utilization of glycerol as a cheap carbon source during cultivation of the thermoplastic producing bacterium Ralstonia eutropha H16 and on the investigation of carbohydrate transport proteins involved herein. Seven open reading frames were identified in the genome of strain H16 to encode for putative proteins of the phosphoenolpyruvate-carbohydrate phosphotransferase system PEP-PTS . Although the core components of PEP-PTS enzyme I ptsI and histidine phosphocarrier protein ptsH are available in strain H16 a complete PTS-mediated carbohydrate transport is lacking. Growth experiments employing several PEP-PTS mutants indicate that the putative ptsMHI operon comprising ptsM a fructose-specific EIIA component of PTS ptsH and ptsI is responsible for limited cell growth and reduced PHB accumulation 53 w w less PHB than the wild type of this strain in media containing glycerol as a sole carbon source. Otherwise the deletion of gene H16_A0384 ptsN nitrogen regulatory EIIA component of PTS seemed to largely compensate the effect of the deleted ptsMHI operon 49 w w PHB . The involvement of the PTS homologous proteins on the utilization of the non-PTS sugar alcohol glycerol and its effect on cell growth as well as PHB and carbon metabolism of R. eutropha will be discussed. Keywords .
